English: The production rule is (a ↦ ab) (b ↦ c) (c ↦ a) with initiator b, iterated for 40 generations. The incidence matrix M [1,0,1; 1,0,0; 0,1,0] has characteristic polynomial f(x) = x³ − x² − 1 and dominant eigenvalue ψ = 1.46557 (the supergolden ratio). The central tile and its three subtiles have areas in the ratios ψ⁴ : ψ² : ψ : 1. The viewport height is 2.8 and the origin is at the eye of the swirl. Empirically, the fractal boundary has box-counting dimension 1.50. Conjecturally, with dim_box(fb) ≈ log_ψ(λ), λ is the real solution of λ³ = 2λ + 2.